lubuntu-rc.xml does not bind volume control keys to pulse audio controls

[Ryan]

Keyboard volume controls do not unmute speaker or headphone volume channels, but only the master channel.

To reproduce:

1. Mute volume by opening pulse audio controls or from the widget in the task bar panel
2. Try to unmute with keyboard by pressing unmute, or by changing the volume.
3. Open alsamixer and note that the master volume is unmuted and the volume is changed, but the speaker and/or headphone volume channel is not unmuted.

To fix, the volume management settings in lubuntu-rc.xml can be changed to

 <!-- Keybinding for Volume management -->
    <keybind key="XF86AudioRaiseVolume">
      <action name="Execute">
        <command>amixer -q -D pulse sset Master 3%+ unmute</command>
      </action>
    </keybind>
    <keybind key="XF86AudioLowerVolume">
      <action name="Execute">
        <command>amixer -q -D pulse sset Master 3%- unmute</command>
      </action>
    </keybind>
    <keybind key="XF86AudioMute">
      <action name="Execute">
        <command>amixer -D pulse set Master Playback Switch toggle</command>
      </action>
    </keybind>

For more info, see

https://ubuntuforums.org/showthread.php?t=1956323
https://askubuntu.com/questions/544754/lubuntu-14-04-unmute-sound-from-keyboard-not-work

[ԜаӀtеr Ⅼарсһуnѕkі (wxl)]

Lubuntu uses lxqt-globalkeys to handle audio hotkeys, which has its own in-built mechanism to handle it rather than relying on a command. Thus, dropping lubuntu-default-settings.